Secure rates in multiband broadcast channels with combating jammers.

We consider the broadcast channel with confidential messages (BCCM) over N parallel Gaussian channels. The transmitter aims at maximizing the sum-rate. The system has two combating jammers, each aiming to enhance the secure rate to one receiver only, while hurting the other receiver by sending Gaussian jamming signals. We cast the problem as an extensive-form game and derive the optimal jamming policy. We show that the jamming strategy is a form of generalized water-filling, and provide theoretical insights on the optimal solution. We provide simulation results to show the convergence of the rate and power allocations, and study the effect of increasing the available power of the transmitter and/or the jammers.